import math

n,m,k,r = map(int,input().split())

ps = []
for i in range(0,n + m):
    p = list(map(int,input().split()))
    ps.append(p)

flag = [False for x in ps]

def distance(p1,p2):
    return math.sqrt(math.pow(p1[0] - p2[0],2) + math.pow(p1[1] - p2[1],2))

rs = []
rs.append([[ps[0]],0])
flag[0] = True

def copy_ritem(ritem):
    res = [[],0]
    res[1] = ritem[1]
    for x in ritem[0]:
        res[0].append(x)
    return res

while True:
    for ritem in rs:
        i = 1
        while i < n + m:
            if flag[i] == True:
                pass
            else:
               dis = distance(ritem[0][-1],ps[i])
               if dis > r:
                   pass
               elif i >= n:
                   if ritem[1] + 1 <= k:
                       next = copy_ritem(ritem)
                       next[0].append(ps[i])
                       flag[i] = True
                       next[1]+=1
                       rs.append(next)
                   else:
                       pass
               else:
                   next = copy_ritem(ritem)
                   next[0].append(ps[i])
                   flag[i] = True
                   rs.append(next)
                   if i == 1:
                       print(len(next[0]) - 2)
                       exit(0)
                   else:
                       pass

            i+=1
    rs.remove(rs[0])
